Data recovery on a Seagate 3TB ST3000DM001 external USB hard drive – March 2016

This Seagate hard drive was brought into our Cape Town lab for data recovery after it developed a faulty and the client was unable to access it. We did some preliminary diagnostics and discovered that one of the heads was fault and unable to read data reliably from the top side of the second platter.

The 3TB hard drive has 6 heads servicing 3 platters, 2 heads per platter. We imaged the good heads first, heads 0,1,2,4 and 5. Head 3 was able to read some data very slowly, but there were a lot of read errors and, after a while, the head failed to read any data at all. Once all of the data was recovered from the good heads we placed the hard drive into our lab environment and removed the original head assembly, replacing it with an identical assembly from a matching donor drive. We were then able to read the unreadable data from head 3 and got a 100% recovery. This drive had already been to two other data recovery labs where it was deemed unrecoverable. We also had to make some firmware fixes to stabilise the drive. See our video below where you can see the yellow blocks turning to green, the unreadable blocks on the original heads over the area of head 3 become readable with the new heads.